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Background Wolff Parkinson White syndrome is responsible of junctional tachycardia and potentially sudden death in children. Precise location of accessory pathway (AP) is crucial to increase safety and success rate of ablation procedures. Known ECG localization algorithms have limited accuracy in children close to 50%. Objective The aim of study was to evaluate a new ECG algorithm relying on maximal pre-excitation (EMP) in children. Methods ECG with EMP (ventricular activation secondary to AP without His bundle activation), induced by atrial pacing or adenosine test/vagal maneuver, was prospectively recorded during an electrophysiological study in 90 consecutive children under 16, in 3 tertiary centers between 2008 and 2020. 3 blinded investigators (1: expert rythmologist, 2: pediatric cardiologist and 3: pediatric cardiologist in training) tested a new algorithm based on EMP to predict AP location and 2 validated control algorithms, from Arruda and Min Baek, relying on basal pre-excitation. Predicted locations were matched with ablation-verified AP location. Sensibility, specificity, negative/positive predictive values and reproducibility, defined as level of agreement between investigators in determining AP location, were evaluated. Results AP were Left sided in 38%, septal in 47% and right sided in 16%. With the new algorithm, predictive accuracy for the 9 exact locations was 91%, 89% and 90% for investigator 1, 2 and 3, respectively. Sensibility was 80-100% for right sided, 95–100% for left sided and 62-100% for septal AP. Concordance between investigators was excellent (k ≥ 0,86). The accuracy for the reference algorithms remain poor (45% for Arruda and 51% for Min Baek) with less concordance between investigators. Conclusion Our new algorithm based on EMP allows accurate and easy to use localization of AP in children. This algorithm can be employed before cardiac catheterization and can allow better evaluation of the benefit/risk ratio of the intervention.

International audience; Pulmonary vein isolation is the mainstay of treatment in catheter ablation of paroxysmal atrial fibrillation (AF). Cryoballoon ablation has been introduced more recently than radiofrequency ablation, the standard technique in most centres. Pulmonary veins frequently display anatomical variants, which may compromise the results of cryoballoon ablation. We aimed to evaluate the mid-term outcomes of cryoballoon ablation in an unselected population with paroxysmal AF from an anatomical viewpoint.

Background: A novel, low flow irrigated radiofrequency (RF) catheter with a diamond cooling tip to enable the physician to perform fast temperature-controlled ablations with rapid lesion assessment using high resolution electrograms (EGM) was evaluated in a first-in-man, prospective, multicenter, single-arm study. Methods: Patients with symptomatic, drug-refractory paroxysmal atrial fibrillation (PAF) underwent pulmonary vein isolation (PVI) with the new DiamondTip Ablation System. All patients were subsequently followed at 7 days, 1, 3, 6 and 12 months post procedure with a subset of patients undergoing remapping within the first 3 months post procedure.

Background Cardiac Resynchronization Therapy (CRT) improves morbidity and mortality in systolic heart failure. Elderly patients are under represented in large clinical trials although incidence of heart failure is high in this population. Method we considered 146 consecutive patients 75 years old with standard indication for CRT implanted between 2005 and 2007. Mean age was 79 yo, 72% males, EF = 27%, ischemic heart disease (IHD) 46%, Atrial Fibrillation 54%, CRT-D: 16%. Minimal follow-up was 12 months. Total mortality, clinical improvement (gain > 1 NYHA class without hospitalization for congestive heart failure) and combined criteria (mortality and clinical improvement) were retrospectively assessed. Results Mean follow-up is 25 +/-12 months. Data are complete for 137 patients (94.2%). Survival rate is 65%, clinical improvement is achieved in 51% and combined criteria in 45%. Independent factors of non response (p Causes of deaths are: terminal heart failure: 35 pts, sudden cardiac death: 1 pt, non cardiac death: 13 pts and unknown: 2 pts. Conclusion CRT is effective in elderly patients. Factors of non response are similar to those observed in younger population. CRT-P appears to be the most suitable device for this population. (Voir tableau ci-dessous) Multivariate analysis OR (IC 95%) Combined criteria Total Mortality Clinical improvement NYHA IV 4,1 (1.5–12.4) 3.1 (1.2–8.5) 2.5 (1–6.6) IHD 2,2 (1–4.8) 3.4 (1.5–7.9) NS CRT-D NS 3.2 (1.2–8.8) NS Atrial fibrillation 2,7 (1.3–5.8) 2.2 (1–5.1) NS No ACEI/ARB 2,7 (0.9–8.8) NS NS Renal failure (creatinine > 10μm/l) 1,1 (1–1.2) NS 1.2 (1.1–1.3) Doses of diuretics NS 1.03 (1–1.1) NS